package com.hycc.base;

import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.locks.ReadWriteLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;

public class ReadWriteLockDemo {
    public static void main(String[] args) {
        MyCache2 myCache = new MyCache2();

        //写入
        for (int i = 1; i <= 5; i++) {
            final int temp =i;
            new Thread(()->{
                myCache.put(String.valueOf(temp),String.valueOf(temp));
            },String.valueOf(i)).start();
        }

        //读取
        for (int i = 1; i <= 5; i++) {
            final int temp =i;
            new Thread(()->{
                myCache.get(String.valueOf(temp));
            },String.valueOf(i)).start();
        }
    }
}

//加锁
class MyCache2{
    private volatile Map<String,Object> map =new HashMap<>();
    private ReadWriteLock readWriteLock =new ReentrantReadWriteLock();

    //存 写
    public void put(String key,Object value){
        try {
            readWriteLock.writeLock().lock();
            System.out.println(Thread.currentThread().getName()+"写入"+key);
            map.put(key, value);
            System.out.println(Thread.currentThread().getName()+"写入ok");
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            readWriteLock.writeLock().unlock();
        }
    }

    //取 读
    public void get(String key){
        try {
            readWriteLock.readLock().lock();
            System.out.println(Thread.currentThread().getName()+"读取"+key);
            Object o = map.get(key);
            System.out.println(Thread.currentThread().getName()+"读取ok");
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            readWriteLock.readLock().unlock();
        }

    }
}

//不加锁
class MyCache{
    private volatile Map<String,Object> map =new HashMap<>();

    //存 写
    public void put(String key,Object value){
        System.out.println(Thread.currentThread().getName()+"写入"+key);
        map.put(key, value);
        System.out.println(Thread.currentThread().getName()+"写入ok");
    }

    //取 读
    public void get(String key){
        System.out.println(Thread.currentThread().getName()+"读取"+key);
        Object o = map.get(key);
        System.out.println(Thread.currentThread().getName()+"读取ok");

    }
}
